(UroToday.com) The CheckMate 032 (NCT01928394) study is a multicenter open label phase ½ trial examining the efficacy of the anti-PD1 antibody nivolumab as monotherapy or in combination with the anti-CTLA4 antibody ipilimumab in several advanced tumor setting. The schema of the study is shown below:
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In this poster, Dr. Sharma and colleagues present updated results from the advanced urothelial carcinoma cohort. Results from the previous data cutoff were published last year1. Objective response rates were 25.6% (Nivo monotherapy), 26.9% (nivo 3 mg/kg and ipi 1 mg/kg – NIVO3/IPI1) and 38% (nivo 1 mg/kg, ipi 3 mg/kg NIVO1/IPI3). Median duration response in all arms was > 22 months. In this updated follow-up dataset, the minimum follow-up was 56.2 months for Nivo monotherapy, 57 months for NIVO3/IPI1 and 26.7 months for NIVO1/IPI3. 93.4% of patients had discontinued therapy by the time of the January 2020 cutoff data. The updated response data from each arm are shown, including specific data on responders only at the bottom of the table.
Investigator assessed PFS data is shown below. In patients with PD-L1 expression ≥ 1%, median PFS was 2.5, 1.6, and 8.2 months with NIVO monotherapy, NIVO3/IPI1, and NIVO1IP3, respectively. In patients with PD-L1 expression < 1%, median PFS was 2.8, 3.0, and 2.8 months with NIVO monotherapy, NIVO3/IPI1, and NIVO1/IP3, respectively.
The median OS 9.9 months with Nivo monotherapy, 7.4 months for NIVO3/IPI1, and 15.3 months for NIVO1/IPI3 (shown below). After two years, 37.9% of nivo monotherapy patients were alive, 27.5% of NIVO3/IPI1 patients were alive, and 41.4% of NIVO1/IPI3 were alive. Median overall survival was longer in patients expressing PD-L1 (12.9 versus 10.4 months for nivo monotherapy, 10.8 months versus 7.4 months in NIVO3/IPI1, and 35.6 months versus 14.9 months in NIVO1/IPI3.
Over 80% of patients in each arm suffered a treatment related adverse event, though more patients had grade 3 or 4 adverse event in the NIVO1/IPI3 arm.
The authors concluded that all arms at this later follow-up time continued to demonstrate clinical activity for patients with advanced urothelial cancer. Antitumor activity was numerically higher in the NIVO1/IPI3 arm. Patients with PD-L1 expression had numerically longer overall survival. The efficacy of NIVO1/IPI3 supports this arm of therapy within CheckMate 901 trial (NCT03036098) comparing nivolumab and ipilimumab against platinum and gemcitabine chemotherapy.
References:
1. Sharma, Padmanee, Arlene Siefker-Radtke, Filippo de Braud, Umberto Basso, Emiliano Calvo, Petri Bono, Michael A. Morse et al. "Nivolumab alone and with ipilimumab in previously treated metastatic urothelial carcinoma: CheckMate 032 nivolumab 1 mg/kg plus ipilimumab 3 mg/kg expansion cohort results." Journal of Clinical Oncology 37, no. 19 (2019): 1608-1616.
Presented by: Padmanee Sharma, MD, PhD, Department of Genitourinary Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX
Written by: Alok Tewari, MD, PhD, Medical Oncologist at the Dana-Farber Cancer Institute, at the 2020 European Society for Medical Oncology Virtual Congress (#ESMO20), September 19th-September 21st, 2020.